Arch-tube safety device.



P. BUWERB.

ARUH TUBE SAFETY DEVICE.

APPLICATION mun rsn.e,1s1-a.

a sums-suns! 1.

SQ 3, it

P. BOWERS.

ARCH TUBE SAFETY DEVICE.

APPLICATION FILED FEB.9,1914.

1 105,397. Patented July 28, 191

2 BHiiBTB-BHEET 2.

PAUL BOWIERS, F STARBUCK, WASHINGTdN.

ARCI-IFTUBE SAFETY DEVICE.

Specification of Letters Patent.

Patented July 28, 1914.

Application filed February 9, 1914. Serial No. 817,646

To all who/1'2 1'2 may concern Be it known that I, PA L Bownns, a citizen of the United States, residing at Starbuck, in the-county of Columbia and State oflVashington, have. invented new and usev:tul Improvements in Arch-Tube Safety De- "vices, of which the following is a specification.

This invention relates to boilers of that type wherein water tubes extend across the fire-box above the grate and which tubes are generally known as arch tubes. These tubes are subjected to the most intense heat and accideii'its frequently oc'curby reason of the fact that the arch tubes burst, causing damage of various kinds necessarily resulting from release of water and steam into the fire-box. j

It-is one of the objects of my invention to provide means, preferably acting auto mati'cally, for closing ingress. to the arch tubes when internal pressure therein is lowcred with respect to boiler pressure by reason of breakage or cracking of the arch tubes so as to out such broken or cracked tube out of service.

Other features and objects of the invention will be more fully described in connection with the accompanying drawings, and will be more particularly pointed out and ascertained in. andby the appended claims.

In the drawings: Figure 1' is a longitudinal vertical sectional View of a locomotive boiler, showing one application of the device of my invention thereto. Fig. 2 is an enlarged sectional contracted view of portions of the boiler and fire-box, showing an arch tube in service.- F ig. 3 is a view similar to Fig. 2, showing the position of the device of my invention when the tube is cut outfof service. Fig. dis a sectional View of the device of my invention detached from the boiler.

. Lige. characters of reference designate similar parts throughout the diderent figures of the drawings.

I have illustrated the device of my invention as applied to a locomotive boiler and to the arch tubes thereof, but I would have it understood that my invention is not limited to this particular utility.

In the drawings, .1 designates the tire.-

boX and '2 the boiler, the fire-box vertical walls being, indicated at 3 and 4 and those portions of the boiler shell to' which refer ence will be made, being indicated at 5 and 6. y

A plurality of tubes,oneonly being shown and indicated at 7, extends from walls 3 to 4tin arched form to support firebrick 8 and the tube 7 C(ll'llllllllllClltCS with the boiler at a relatively low point, at its forward end, and at a relatively high point at its rearward end, thereby causing a flow through the tube in the direction of the arrow, when thetube is in service. Breakage of the tube, as indicated at 9, would cause the steam and water to rush into the firebox and force the door in a manner to do the usual damage resulting from such breakage.

In accordance with the 'mostimproved form of my invention, I provide devices at each end of the tube 7, which are responsive close ingress thereto from the boiler when pressure in the tube decreases with respect to the pressure in the boiler.

As illustrated more particularly in Figs. :2 and 3, 1O designates a valve closure of the truncated conical type, which is adapted to seat against the reemed terminal 11 of the tube 7. As the devices at both ends of the tube are similar in construction and opera -tion'. a description of one will suffice. In

order to mcrease the area of the closure 10. which is responsive to boiler pressure, I provide the same with a head 12 against. the face 18 of which flow from the boiler is effective to efi'ect closing action, it being understood that-the main area will be the back of the closure, which is indicated at 14. The closure 10 is provided with a stem 15, which is preferably exteriorly threaded to receive a nut 16, the adjustment of which regulates the extent of openingmovement of the closure 10, in a manner which will presently appear. The stem 15 is provided with a reduced guiding portion 17, which is 'n'eterably extcriorly threaded to receive a nut 18. A guide for the closure 10 is provided in the form of a rectangular frame 19 through one wallet which, as indicated at 20. the stem 17 is's'lidably mounted, so that the closure 10 will be held to a straight line oi movement axially of its stem. In order to retain the closure 10 in a normal open position, I interpose a relatively weak spring 21 .to lowering of the pressure in the tube to I between the nut 18 and the frame portion.

20, openingimovement of the closure being limited by abutment of the nut 16 against little or no leakage would result. Further? the part 20 of the closure guide 19. lhe closure guide 19 is provided with a threaded. stud. 22, which is turned into a plug 23 in the shell wall 6. The plug 23 is shown threaded in thew'all 6, and the tl'irea ded engagement of the stud 22 afiords a relatively extensive range of initial adjustment of the closure 10 with respect to the seat of the tube It will now be clear that if any one of the arch tubes 7 became broken or cracked so that interior pressure therein was I less than boiler pressure, the Water and steam seeking admission to such broken tube would instantly and automatically. seat the closures 10 at both ends of such tube, thereby cutting the tube out of service so that more, boiler pressure would retain the'closure seated so as tomost effectively out such tube out ofservice until it could be removed.

It will be seen that installation of the deviw of my invention requires'aminimum expense, and as the-closures are normally inactive and only become active responsive to boiler pressure,

lot dependent upon springs or other mechanism and therefore they-canbe relied upon .to efiectiyely perform theinfunction until repairs e'an' be made. i Y. Y

tWhile I have herein shown and described. one specific form of my invention, ll donot wish to be limited thereto except for such limitations as the claims may import. fll[ claim:-T y

1. In combination, a boilenprovided with a fire-box, a tube-extending across the firebox and communicating at 1ts ends with the on the stem, a guide .mounted on the boiler and having guidtheir certainty of action is amass? interior of the boiler, and a valve device at each end. of the tube responsive to boiler pressure for automatically and simultaneously closing ingress to both ends of the tube from the boiler when pressure in the former decreases with respect to pressure in the latter, substantially as described.

lneombination, a boiler provided with a firebox, a tube extending across the firebox and communicating at its ends with the interior of the boiler, a valve device responsive to boiler pressure for automatically closing each end of the tube against ingress thereto from the boiler, and springs for nor mally holding said valve devices in open posubstantially as described.

sitions a boiler provided with 3. In combination,

a fire-box, a tube extending across the the.

box and having its ends projecting intothe boiler, and a valve closure structure-for each end of the tube each, comprising a closure having a stem, an adjustable abutment nut frame adjust'ably ing engagement with said stem, and a sprung coacting with to normally from the tube end, substantially as described.

. lln testimony that I claim the foregoing the stem and the guide frame hold the valve closure away 

